The present invention is directed to a cylindrical brush alignment device, particularly for use in association with a surface maintenance vehicle.
Surface maintenance vehicles and cleaning devices have a long history subject to gradual innovation and improvement toward improved and oftentimes automated performance in removing debris and contamination from floors and other surfaces to be cleaned. These vehicles and devices may be self-powered, towed, or pushed, and/or manually powered and may carry a human operator during cleaning operations. Such vehicles and devices include scrubbers, extractors, sweepers and vacuums, as well as combinations thereof, intended for cleaning, scrubbing, wiping and/or drying a portion of a substantially flat surface both indoors and outdoors. Many such vehicles and devices employ one or more rotating brushes for sweeping debris from a floor and/or, in conjunction solution of water and a detergent, providing scrubbing action via one or more of the rotating brushes. The brush assembly of such prior art cleaning vehicles may mount to the vehicle at any convenient location. However, due consideration of potential cooperation and/or synergy with other cleaning apparatus used by the surface maintenance vehicle typically dictates that the brush assembly couples at or near the middle or front portion of the vehicle. Cleaning solution(s) may be pumped or sprayed via traditional means to the surface near the rotary scrub brushes operating from a lower portion of the vehicle. Some of the rotary scrub brushes may have a substantially vertical axis of rotation and others may have a substantially horizontal axis of rotation. The configuration between a pair or set of these rotary scrub brushes are generally spaced apart so as to cooperate toward the collection and removal of particles and debris from the surface using consistent contact with the surface to be cleaned and the bristle ends of each of said rotary brushes. The length of the cylindrical brushes are often sufficiently wide to at least cover the path width of the wheels of the cleaning vehicle.
Floor scrubbing vehicles are widely used to clean the floors of industrial and commercial buildings. They range in size from a small model which may clean a path ranging from perhaps 15 inches up to 36 inches wide controlled by an operator walking behind it, to a large model cleaning a path as wide as five feet controlled by an operator riding on the machine. In general, these machines have a wheeled chassis which contains, in addition to power and traction drive means, a tank to hold clean scrubbing solution and a vessel to hold debris recovered from the surface being scrubbed. A scrub head is attached to the chassis by an articulated linkage system, and may be located in front of, under or behind the chassis. The scrub head contains one or more rotating scrub brushes and means to power them. These brushes may be either flat disc brushes that rotate about vertical axes or they may be cylindrical brushes rotating about horizontal axes. Both systems have their advantages and disadvantages, and both are widely used. An early example of such a surface maintenance device includes U.S. Pat. No. 3,702,488, which is incorporated by reference herein.
In addition, rotating cylindrical brush assembly and related drive and support structures for cleaning vehicles have been known and used in the art, such as that disclosed in U.S. Pat. No. 5,515,568 assigned to Tennant Company of Golden Valley, Minn. U.S.A. which issued on May 14, 1996 to Larson et al. and the contents of which are incorporated by reference herein, and U.S. Pat. No. 6,035,479 also assigned to Tennant Company, which issued on Mar. 14, 2000 to Basham et al. the contents of which are incorporated by reference herein. In these prior art references, a brush assembly includes a mounting plate mechanically connected to the brush assembly via many individual traditional threaded shank members and corresponding washers and threaded nuts and the like to firmly couple a brush assembly to the cleaning vehicle. The resulting metal-on-metal contact between the bolts, slots, washers and nuts provides a compression force of sufficient magnitude to ensure that the rotating brush assembly attachment cannot separate from the vehicle, but mainly depends upon the degree of tightening of individual bolts between diverse subcomponents of the assembly. In the event a brush requires taper adjustment, presumably each nut and bolt pair and other connecting components must be loosened and/or completed removed (and accounted for) and/or complete removal of at least one end of the brush assembly from its respective rotational mounting location. In addition, associated drive motor and motor coupling members may require time consuming partial disassembly and/or removal with possible risk of lost of parts.
If the operator is unable to release any of the connecting components or is unable to adequately tighten same, the operator may have to temporarily depart the facility being cleaned unless and until same may be rectified. If in fact the connecting components are overly loose, the brush assembly may disengage from the surface maintenance vehicle during cleaning operations with dire results for the facility, the surface being cleaned, the vehicle and perhaps even the operator of the vehicle with additional downtime, repair efforts, and/or adjustment resulting as a direct consequence.
Accordingly, the recited prior art approach as well a many other known assemblies rely on manually developed force between several opposing surfaces at diverse locations using conventional hardware. Unfortunately, as in the reference immediately above, the compressive forces required to fully assemble such prior art rotary brush assemblies are typically not susceptible of manual tightening of a knob or wing nut. Instead, diverse tools, both manually operated and independently powered, must be applied to each connecting subcomponent first during partial (or complete) disassembly of the subcomponent, during adjustment of the brush taper by adjusting the entire brush assembly relative to the vehicle and/or the surface to be cleaned, and later during re-attachment of each connecting subcomponent. Finally, such prior art approaches must be field tested to confirm that the adjustment to the brush taper effectively improved the sweeping operation of the surface maintenance vehicle. If not, then the entire procedure (i.e., partial/complete disassembly of each subcomponent, adjustment of the brush assembly relative to the vehicle and/or surface to be cleaned, and during re-attachment of each connecting subcomponent) must be performed again, perhaps repeatedly, until such adjustment is deemed adequate following field testing.
The invention herein is primarily concerned with scrubbers that use two counter-rotating cylindrical brushes. The brushes are preferably set parallel to each other and are closely spaced, with their axes of rotation being horizontal and generally transverse to a longitudinal axis relative to the intended direction of travel of the vehicle. A major advantage of this configuration is that the cylindrical brushes, while scrubbing the floor, act cooperatively to also sweep up small particles and debris that may be on the surface being scrubbed and deposit them in a debris tray or other receptacle or vessel. Cylindrical brush mounting assemblies used on such vehicles may include alignment devices for adjusting the relative orientation of the brushes. These brush alignment devices are necessary to adjust the brush into equal ground contact along its longitudinal length. Known brush alignment procedures have typically required at least partial disassembly of the brush assembly from the maintenance vehicle, an inefficient adjustment procedure briefly described above and requiring a vehicle operator to halt cleaning operations, apply diverse tools to uncouple connecting parts of the brush assembly from the vehicle and the like with resulting loss of cleaning effort during such service and the potential for parts to be lost, misplaced or re-connected improperly or without adequate force.
Thus, the present invention addresses a long felt need for a brush alignment assembly which permits rapid, efficient and accurate adjustment of the brush alignment without requiring disassembly of the working components of the brush assembly and without disturbing the brush or the rotational mounts therefore.
The present invention provides an adjustment mechanism and methods for adjusting the alignment of a powered cylindrical brush relative to a surface to be maintained or cleaned by the vehicle. The device is preferably disposed upon the idler-side of a powered rotating cylindrical brush assembly and the adjustment preferably occurs via use of an member analogous to an eccentric cam, and said cam member is designed to provide a range of motion, or pivot location, through or about which the idler-side mounting location of the cylindrical brush may be adjusted to improve contact with the surface and/or to improve the degree of mechanical cooperation between at least two counter-rotating cylindrical brush assemblies disposed on a single surface maintenance vehicle.
Another aspect of the present invention improves brush taper adjustments by not requiring disassembly of any connecting components for operating the rotating cylindrical brush assembly during cleaning operations, except for partial release of mounting force to a housing for said brush assembly. Such housing member often includes a side cover member for each brush which supports the brush relative to the housing, and said side cover typically promotes manual access to more readily service portions of the brush assembly such as other brush mounting components and any drive gear associated thereto. Such a side cover is not required in practicing the present invention (i.e., to adjust the spacing between an axis of rotation of a rotating cylindrical brush relative to a surface to be brushed). As a result, an efficient adjustment process is provided which permits the operator to quickly adjust the brush taper. As used in this disclosure the term xe2x80x9ctaperxe2x80x9d has its usual and ordinary meaning, that is a gradual decrease in the thickness or width of an elongated object. Adjustment of the brush taper is required from time to time in the course of operating a surface maintenance vehicle.
The apparatus and methods of the present invention are intended to readily accommodate rapid brush taper adjustment in the course of surface cleaning operations by a single manual operator using no tools or using no more than a single rudimentary adjustment instrument, or tool, operating upon a single adjustable mounting location to change the state of the single adjustable mounting location from a partially-released state to a fully-coupled state. In an alternative embodiment, such tool may be integrally formed with said single adjustable mounting location and/or adjacent structure and thereby shall be readily available for immediate use, as desired. In this alternate embodiment, such integrally formed tool may comprise a large wing-type nut and lock washer in combination, or an elongate lever handle, or a modified lever handle that folds into a recess formed adjacent the single mounting location. Of course, such a lever handle may include spring biasing to ensure that said lever handle remains in a retracted position when not is use to reduce the risk of an inadvertent transition from the fully-coupled state to the partially-released state. The inventors hereof confirm that each such adjustment may be performed rapidly by said single operator expending not more than a few minutes effort.
Yet another aspect of the present invention is to provide indicia upon an idler-side brush assembly cover plate, or housing, and/or to the adjustable eccentric cam member to provide reference indicia to the operator or technician during the alignment or adjustment process of the brush taper as taught, enabled, disclosed and claimed herein.
The present invention thus teaches, enables and discloses an improved, readily adjustable mechanical coupling for a rotary brush assembly usable in a surface maintenance vehicle. Such a vehicle includes those self-powered and manually powered cleaning vehicles applied to the task of removing particles and debris from a cleaned surface and preferably include all such vehicles using a rotary brush assembly. Such a surface may comprise interior or exterior flooring having some limited porosity but preferably comprising finished concrete (whether painted or sealed), asphalt, ceramic tile, resin-based tile, and the like and including most types of flooring typical of commercial and industrial-grade facilities. However, the teaching hereof finds application in diverse handling of particles and debris. The present invention is useable in diverse locations such as gymnasium floors, indoor and outdoor tennis courts, poolside flooring and the like. In addition, the present invention may be used for debris removal following spectator events at diverse indoor facilities or outdoor facilities where practice of the present invention speeds elimination of undesirable particles and debris present on, in and around such facilities.
During cleaning operations, as the maintenance vehicle is propelled forward over a portion of a surface to be cleaned, when the bristles of a rotary brush contacts the surface to be cleaned typical degradation and wear occurs to the bristles that eventually may change the effective area of contact between the bristles and the surface. The improved, readily adjustable mechanical coupling for the rotary brush assemblies taught herein provides a rapid and reliable method of accurately adjusting the orientation of the rotary brush thereby promoting improved contact between the bristles and the surface and accordingly, more effective removal of debris from said surface. Due to the design of the improved, readily adjustable mechanical coupling of the present invention, the rotary brush assembly remains operable and intact and securely coupled to its mounting locations on the surface maintenance vehicle while the brush taper adjustment occurs.
With respect to the variety of cylindrical brush assemblies and brushes available for use in conjunction with the present invention, U.S. Pat. No. 6,125,495 issued Oct. 3, 2000 and U.S. Pat. No. 6,003,186 issued Dec. 21, 1999 each of which is incorporated herein by reference should provide adequate detail regarding specifics of the construction, operation and design considerations for rotary brush assemblies. Both of the cited patents are owned by Tennant Company, assignee of the present invention. Although the present invention may be practiced using any variety of rotary brush having a substantially horizontal axis of rotation and operating in a surface maintenance vehicle. As noted in the patent references noted immediately above, the size, shape, composition and pattern(s) of the bristles of a substantially cylindrical rotating brush and the speed of rotation of same, including different rates of rotation between adjacent brushes may be used to improve and control the debris removing performance of surface cleaning vehicles such as those using the teaching of the present invention. In addition, various debris-handling features may be added to and used in conjunction with the present invention such as baffles, deflector shields, resilient flanges or conduit and the like may be designed and/or implemented to direct, redirect or collect such particles and debris in a specified location.
Those of skill in the art will recognize that various other structure may serve in lieu of the functionality provided by a eccentric cam member and secondary cam member as taught and illustrated herein. For example, a single cam member effectively integrating the function of the dual cam structure taught herein may be used to practice the present invention. While the drive means for the rotary brushes is depicted as an electrical motor mechanically coupled to drive a single brush into rotation, a single motor could drive more than one rotary brush. Also, the motor could operate using electricity, combustible materials, or could be driven via the same power source which propels the maintenance vehicle forward and may be articulated so that the rotary brush assembly may be independently moved up, over or down or placed in a variety of useful configurations relative to the surface maintenance vehicle. One object of the invention is to provide such an articulated brush assembly for a surface maintenance vehicle which is tolerant of wear forces imparted to the brush assembly, including the typical degradation and wear to bristles comprising said rotary brush.